RESUMEN
Covelently labeled pyrene excimer molecular beacon (MB) with cholesterol moiety has been developed for enhanced the cellular delivery of MB.(1) Pyrene units were covalently attached into adenosine and incorporated to oligonucleotides at the complementary locations in opposite strands in the middle positions of hairpin stems. The system behaves as an effective MB that changes color from green to blue upon duplex formation. A cholesterol unit was also attached into a free terminus of one of these hairpins. The cholesterol-linked MBs enhanced the cellular delivery of the MBs and showed similar cell permeability to conventional transfection methods. These structurally simple cholesterol-based MB systems, which can be synthesized very efficiently, have good potential for opening up new and exciting opportunities in the field of in vivo biosensors.